Page 35 - Spring 2019
P. 35

covery of the relationship between room volume, materials, is long in tune, it is lower in level, which strikes a different
and reverberation. Built in 2015, the Philharmonie de Paris balance between reverberance and clarity. In an interview
is far from rectangular. Its form is most si.rnilar to a “vine- with Kahle (personal communication, 2018), he noted that
yard” style hall, which features a centralized orchestra po- the high seat count was one of the primary acoustical design
sition surrounded by audience seated in shallow balconies. challenges and this necessitated the parametrically prescrip-
Led by Iean Nouvel (architect) and Harold Marshall (design tive design brief. In his words, “an orchestra has a limited
acoustician), the design team was selected by competition sound power, which you have to distribute over more peo-
and was provided with a detailed and prescriptive acoustical ple...and if you share it, you get less of it.” The seating ar-
brief by the owner’s acoustician (Kahle Acoustics and Altia, rangement keeps the audience closer to the musicians, which
2006). Sabines scientificallybased acoustical design input for heightens the sense of intimacy. Lateral reflections are pro-
Boston Symphony Hall was li.rnited to its ceiling height. On vided by balcony fronts, although the distribution of lateral
the other hand, the design of the Philharmonie de Paris was energy and ensemble balance vary more between seats due to
based on decades of research about concert hall acoustics. the shape of the room and position of the orchestra. Concave
How do these halls, built under such different circumstances, wall surfaces are shaped to scatter sound and avoid focusing.
compare with each other acoustically? The lengthy but relatively less loud reverberation is gener-
Boston Symphony Hall is known for “S generous reverber_ ated by an outer volume-that is not visible to_the audience.
. . The same orchestra playing the same repertoire will sound
ance, warmth, and enveloping sound. Its 2,625 seats are dis- _ _ _ _
. . completely different in Paris compared with Boston, and the
tributed across a shallowly raked floor and two balconies that _ _ _ _ _
. . quality of the listening experience will depend on where one
wrap around the sides of the room, which measures 18,750 _ _ _ _ _
3 . . is sitting, the music being performed, and, most of all, the
m in total volume. If the seats were rebuilt today, code re- _ _ _
. . . listeners expectations and preferences.
quirements and current expectations of comfort would sig-
nificantly reduce the seat count. The lightly upholstered seats Table 2 shows a comparison of parameters measured in both
are acoustically important for preserving strength and re- halls. The numbers show some interesting relative differenc-
verberance (Beranek, 2016). Heavy, plaster walls reflect low- es but do not convey the perceptual significance of these dif-
frequency energy and help to create a warm timbre. The hard ferences or predict how someone would perceive the acous-
and flat lower side walls and undersides of shallow side bal- tics of either hall from a particular seat. Standard deviation
conies provide strong lateral reflections to the orchestra seat- from the average measured parameters should be at least as
ing level, and statues along the ornamented upper side walls important as the averages, especially for spatial parameters,
and deeply coffered ceiling promote diffuse late reflections although this information is rarely published. None of the
throughout the room. The large volume above the second measured parameters describe timbre, ensemble balance, or
balcony fosters the development of late reverberation that is blend. Although the parameters do impart meaning, espe-
long, relatively loud, and decays smoothly. The perception of cially in the context of listening observations and an under-
clarity in the room varies by listening position and the music standing of how architectural features in the room impact
being performed. The Boston Symphony Orchestra is also the acoustics, they do not describe the complete acoustical
one of the worlds best orchestras, and it knows how to high- story or provide a meaningful account of the halls’ dramatic
light the halls acoustical features, particularly for late clas- differences.
sical and romantic era repertoire.
Table 2. Average mid-fiequency parameters measured in Boston Symphony Hall and
The Philharmonie de Paris seats Philhflrmvnie 46 P1111"-V
2,400 in a total volume of 30,500
hhs, which is over 60% larger than ‘ 1”
Boston Symphony Hall. One of _ 0-“
the results of this significant dif- “-10
ference in size is ma‘ although Data for Boston Symphony Hall from Ben1nek(Z004) and for Philharmonie de Paris from Scelo at al.
. . ) . (1015).
the Philharmonies reverberation
Spring 2019 | Annuslzlcl Tnduy | an















































   33   34   35   36   37